[Impression materials and the wettability of dentin surfaces]

Two reversible hydrocolloidal impression materials as well as two light-bodied polysulfide and silicone impression materials were tested with regard to their properties of coating plain ground dentin surfaces. With a wet surface, hydrocolloids produce flatter contact angles between dentin surfaces and the impression material, i. e. a more effective coating than polysulfide and silicone impression materials. The conditions are reversed with dry dentin surfaces and those pretreated with silicone oil. If the dentin surfaces of which an impression is to be taken are treated with silicone oil, coating is less effective with all impression materials tested.